1. Field of the Invention
This invention relates to an animal food product and a method for making such an animal food product and in particular, to a co-extruded dual component animal food product of the type comprising an outer component, including carbohydrate, lipid and protein and an inner cream texture component encapsulated within the outer component by the co-extrusion process.
2. Description of Prior Art
It is known to provide such co-extruded dual component animal food products in which the inner component comprises a cream textured matrix which is formed without an aqueous phase and has a total moisture content of less than about 15% by weight. The major feature of this inner component is that firstly it contains a considerable amount of lipid, namely, fat, and secondly there is no water phase. A typical product is that described in U.S. Pat. No. 6,117,477 (Paluch). This patent specification clearly teaches away from the use of an aqueous phase in the inner component. It has long been appreciated that an aqueous phase would be desirable for the number of water soluble additives that could then be used. It has also been appreciated that, for example, as suggested in U.S. Pat. No. 4,847,098 (Langler) to do this, you would require extra stabilisers and emulsifiers. A further problem with the use of lipids in the inner components is that anti-oxidants are usually required. Thus, conventional wisdom taught away from the use of low viscosity and aqueous phase inner components in dual textured co-extruded food products. Heretofore, people have not been successful in providing such an aqueous based inner component. Essentially, the problem is the incorporation of water soluble in the inner component in sufficient quantities so as to provide a suitable product. Heretofore, conventional wisdom has suggested that high moisture content means a product that is unstable in respect of microbial growth and effectively separation stability. Further, as explained above, water tends to leak from the inner component to the outer component or shell-like covering causing it to become soggy.
Generally speaking, such animal food products should contain a number of ingredients which are functional, that is to say, which help with the stabilisation, taste and general appearance and organoleptic properties of the product and active ingredients which can be loosely defined as minerals and vitamins or, for example, various healthcare products such as laxatives and coat improvers.
Generally speaking, the extrusion process is relatively simple and comprises a twin screw extrusion system which allows the inner component to be pumped into the centre of the outer component which is effectively a rope and then the composite filled rope is divided by a crimper into desired sizes. A typical example of such an extruder is that described in U.S. Pat. No. 4,900,572 (Repholz et al).
Another typical example of such a food product, although this one is for human consumption, is described in U.S. Pat. No. 5,643,623 (Schmitz et al) which describes an inner component containing an anti-oxidant.
In accordance with the invention, there is provided a co-extruded dual component animal food product of the type hereinbefore described in which the cereal comprises at least 60% by weight of the outer component, the outer component has a total moisture content less than 5% by weight of itself, the inner cream textured component comprises a stable continuous emulsion of water soluble additives in an aqueous phase, and hydrocarbon soluble additives in a lipid-free hydrocarbon phase and in which the inner cream textured component has a moisture content of between 8.0% and 16% by weight of itself.
Ideally, the aqueous phase comprises a high solids content sugar syrup containing at least 60% by weight sugar with the sugar syrup comprising sugar and water in the ratio of between 60:40 and 90:10 and ideally of the order of 80:20. The sugar syrup content of the inner component is generally between 25 to 55% by weight of the outer component and preferably of the order of 40% by weight of the inner component.
Ideally, the hydrocarbon phase is liquid paraffin or petroleum jelly.
Ideally, the hydrocarbon phase is between 25 and 55% by weight of the inner component and is often of the order of 40% of the total weight of the inner component.
The water soluble additives comprise one or more of:
calcium carbonate,
dipotassium phosphate,
manganous sulphate monohydrate,
zinc chelate,
Inositol,
folic acid,
taurine,
pantothenic acid,
potassium sorbate.
tricalcium phosphate,
ferrous sulphate heptahydrate,
copper chelate,
Niacin,
herbal extracts,
plant-based extracts,
caramel, and
sodium benzoate.
Similarly, the hydrocarbon soluble additives comprise one or more of:
vitamin A palmitate,
vitamin oil D,
di-xcex1tocopheryl acetate,
flavourings,
glycerol,
acacia gum.
The outer component, as well as cereal, additionally comprises one or more of the following:
mineral supplements
herbal extracts, and
plant-based extracts.
The inner cream-textured component may include particulate additives insoluble in water and hydrocarbons, which particulate additives may comprise an inner core encapsulated in a water and hydrocarbon insoluble outer shell.
Further, the invention provides a method of producing a dual textured animal food product by co-extrusion comprising:
preparing a dry mixture of carbohydrate protein and lipid including at least 60% by weight of dry cereal;
ensuring the dry mixture has a moisture content of less than 5.0% by weight;
preparing an aqueous phase solution of water and water soluble additives;
preparing a hydrocarbon phase of a lipid-free liquid hydrocarbon and hydrocarbon soluble additives;
combining the aqueous and hydrocarbon phases in proportions such as to achieve a total moisture content for the emulsion of between 8% and 16% by weight;
homogenising the aqueous and hydrocarbon phases to form a continuous stable emulsion, the homogenising comprising the steps of adding the hydrocarbon phase to the aqueous phase in discrete batches mixing them to form a continuous stable emulsion, the amount of each batch of the hydrocarbon phase not exceeding 10% by weight of the liquid to which it is added;
co-extruding the dry mixture as an outer component with the continuous stable emulsion as an inner cream-textured component; and
crimping and cutting the extrudate into discrete pillow shapes.
Ideally, in this method, the additives are dissolved in the appropriate phase in discrete batches.
In the method according to the invention, when the weight of additives to be added to a phase exceeds 10% by weight of the phase, the additive is dissolved in the phase in batches not exceeding 10% by weight of the phase to which it is being added.
Generally speaking, the method comprises:
mixing sugar and water in the ratio of at least 60:40 by weight to form a base aqueous phase and then adding additional water soluble additives to form the aqueous phase.
Ideally, after the continuous stable emulsion is formed, further additives both water and hydrocarbon soluble dissolved in glycerol are added and homogenised with the stable emulsion. Ideally, the aqueous phase comprises a high solids content sugar syrup containing at least 60% by weight sugar and the sugar syrup may comprise sugar and water in the ratio of between 60:40 and 90:10. The ratio of sugar to water is often of the order of 80:20 and generally the sugar syrup content of the inner component is between 25 to 55% by weight of the inner component and is preferably of the order of 40% by weight.
In the method, the hydrocarbon phase is liquid paraffin and comprises between 25 and 55% by weight of the inner component and may often be of the order of 40% of the total weight of the inner component.
Ideally, the water soluble additives comprise on or more of:
calcium carbonate,
dipotassium phosphate,
manganous sulphate monohydrate,
zinc chelate,
tricalcium phosphate,
ferrous sulphate heptahydrate,
copper chelate,
niacin,
inositol,
folic acid,
taurine,
pantothenic acid,
potassium sorbate,
herbal extracts,
plant-based extracts,
caramel,
sodium benzoate.
Further, the hydrocarbon soluble additives comprise one or more:
vitamin A palmitate,
vitamin oil D,
di-xcex1tocopheryl actetate,
flavourings,
glycerol, and
acacia gum.
The outer component additionally comprises one or more of the following:
mineral supplements,
herbal extracts,
plant base extracts, and
lecithin.
In another method according to the invention, the inner cream textured component has added thereto particulate additives insoluble in water and hydrocarbons.
When particulate additives are added, they comprise an inner core encapsulated in a water and hydrocarbon insoluble outer shell.